I recently hooked up a DVD player to this TV set. When i operate the player it works fine through the set. When I turn it off and try to watch cable programming through the set I can't get cable reception. When I disconnect the DVD hookup from the TV the cable reception comes back. Is there some sort of setting in the TV to help me watch both a disc and then switch to cable programming without having to disconnect the DVD hookup from the TV, Naturally, I turn off the DVD whan I want to watch cable.